1. Field of the Invention
This invention relates to a heat-resistant silicone block polymer.
2. Description of the Prior Art
Heat-resistant silicone block polymers obtained from arylsilsesquioxane represented by the following general formula (1): ##STR1## wherein R' is an aryl group and n is a positive integer of 25 to 500, and a silicone compound represented by the following general formula (2): ##STR2## wherein R" is an alkyl group or an aryl group, Y is a halogen atom or a hydroxyl group, and m is a positive integer of 1 to 1,000 (U.S. Pat. No. 3,294,737) and those obtained from methylpolysiloxane having a number mean molecular weight of 9,000 to 10,000 represented by the following general formula (3): ##STR3## and a silicone compound represented by the following general formula (4): EQU XR"'.sub.2 Si(CH.sub.2).sub.l (R.sub.2 SiO).sub.m Si(CH.sub.2).sub.l SiR"'.sub.2 X (4)
(Japanese Patent Application Kokai (Laid-open) No. 56-828) are well known. However, all of these silicone block polymers have a substantial flexibility but have a poor heat resistance.